kittens male or female

Question
I read something that says you have to wait until the kittens are 4-5 months to tell their gender.  I will be picking up three kittens tomorrow, and I want all female so they won't spray.  Is this correct information???

Answer
Generally males that are not neutered are more likely to spray but females if provoked in certain ways may also mark with inappropriate peeing. In either case, one of the most important things to do is spay females and neuter males, no later than 6 months of age.

And no, you do not have to wait until they are that old to determine gender but if you aren't too familiar with what you are looking at it will be tougher at younger ages. Here is a picture of a male and a female:
http://www.vetmed.wsu.edu/clientED/kittenSex.asp

In the male the anus is further away from the penis and teh testicles are small rounded ares in between. In the female the anus is closer to the vagina which appears sort of like a slit. But remember, males do not always spray. I have had several neutered males and they NEVER sprayed.